Applying Manure Before Seeding Alfalfa

Applying Manure Before Seeding Alfalfa
April 7, 2017

If you're looking for a place to spread manure, a heavy dose before planting alfalfa can pay big dividends.

Applying manure before seeding alfalfa may seem counter productive since alfalfa is not likely to benefit from any nitrogen in the manure, but manure also is rich in phosphorus, potassium, sulfur, and many micronutrients that alfalfa needs in large quantities.

Research studies show that applying as much as 12,000 gallons or 50 tons of dry manure per acre before planting alfalfa can boost alfalfa yield more than commercial fertilizers applied at the same nutrient levels. And manure has been found to increase yield on both low and high fertility soils, while sometimes higher fertility soils have not responded to commercial fertilizer. Other factors like improved soil tilth, increased soil microbial activity, micronutrients, and early nitrogen availability may be the reason manure increases alfalfa yield so well.

Do not heavily apply manure prior to alfalfa seeding if you also plant a companion crop like oats that you plan to harvest for grain. It is likely to lodge and smother much alfalfa. If you cut the companion crop early for hay, though, it will be alright. Also be careful to avoid compacting the soil with heavy manure-application equipment.

Determine how much manure to apply based on a soil test of nutrient needs and a test of manure nutrients. Mix manure well into the soil using tillage, making sure to prepare a firm seedbed so new alfalfa seedlings will emerge rapidly and vigorously. Also, plan your weed control program carefully since manure can also stimulate weed seedlings. Proper timing of seeding, firm seedbeds, and herbicides or clipping can control weed pressure.